...off the North Carolina coast in the “Graveyard of the Atlantic,” just waiting to be found. A green, 47-foot-long creature of the deep called the Alligator  an engineering marvel of the Civil War that helped usher in a new era in naval warfare. A secret weapon that captured the attention of a president and can claim a proud place in history as the U.S. Navy’s first submarine.

Conceived by the French inventor Brutus de Villeroi and constructed in Philadelphia in 1861, the Alligator was built to combat Confederate ironclad warships and clear harbor obstructions. Its design was as daring as it was innovative. The first operational submarine to have an air purifying system and the ability to deploy a diver while submerged, the Alligator was in many ways the forerunner of today’s subs. But in April 1863, while being towed south to take part in the attack on Charleston harbor, the Union sub was caught in a fierce storm and cut loose off Cape Hatteras.

It hasn’t been seen since.

But the Alligator has not been forgotten. The National Oceanic and Atmospheric Administration, Office of Naval Research, Navy and Marine Living History Association, universities, museums and a dedicated team of historians, naval experts, engineers, modelers, teachers and students from across the nation have joined forces to find this historically important vessel and uncover its secrets.